Compressor with built-in oil separator

ABSTRACT

A compressor with a built-in centrifugal oil separator is characterized in that the oil separator is formed between a first member and a second member constituting a compressor by the coupled structure of the first member and the second member. In the compressor, by simplifying the structure of the oil separation part, the productivity can be improved, the cost can be reduced, and the freedom of the design of the discharge port position can be ensured.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a compressor with a built-in oilseparator, and specifically, to a compressor with a built-in oilseparator which intends to simplify the oil separator built-inmechanism, decrease the number of parts, facilitate the assembly, reducethe cost, etc.

BACKGROUND ART OF THE INVENTION

As a conventional compressor, for example, as a compressor incorporatedinto a refrigeration system in an air conditioning system for vehicles,known is a compressor with a built-in oil separator in which acentrifugal separation type oil separator is incorporated into thecompressor (for example, Patent document 1). In the conventionalcompressor with a built-in oil separator, for example, as depicted inFIG. 6 with an example of a case of a scroll-type compressor which has acompression mechanism 103 comprising a fixed scroll 101 and a movablescroll 102, a centrifugal type oil separator 107 is incorporated in arear casing 106 forming a discharge chamber 105 into which gas (forexample, refrigerant gas) compressed by compression mechanism 103 isintroduced through a discharge hole 104. In such an oil separator 107, astructure is employed wherein cylindrical cylinder (oil separationchamber 108) is provided in casing 106, along its axis a separation pipe109 is inserted or press-fitted, and its upper end side is fixed orengaged by a snap ring 110. Since the oil separation part is providedonly in casing 106 and the oil separation part is formed by machineprocessing, a seal bolt 111 is required in order to keep the insidepressure. Further, a discharge port 112 connected to outside of thecompressor (to an external tube) is communicated with a space formedbetween the upper part of separation pipe 109 and the lower end of sealbolt 111.

The gas compressed by compression mechanism 103 is discharged intodischarge chamber 105 through discharge hole 104 provided in the fixedscroll, and the gas in discharge chamber 105 containing oil isintroduced into oil separation chamber 108 through communication hole113. The introduced gas is rotated around separation pipe 109, andseparated into gas and oil by utilizing the centrifugal force. Theseparated gas passes through the inside of separation pipe 109 anddischarged through discharge port 112, and the oil separated by thecentrifugal force is stored in the lower oil storage chamber 115 throughlower hole 114 (oil return hole). The oil stored in oil storage chamber115 is returned to suction chamber 117 through orifice 116. Patentdocument 1: JP-A-11-93880

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

In the above-described conventional oil separator structure, there arethe following problems.

Because it is necessary to process by machine all of oil separationchamber 108 (cylinder part), lower hole 114 (oil return hole), theinsertion part or the press fitting part for separation pipe 109, thescrew part for seal bolt 111, etc. and there are many machine processingparts, the productivity is not good and the cost is high.

Further, because parts such as separation pipe 109 and seal bolt 111 arenecessary and the entire length of oil separation chamber 108 becomesrelatively great, the process ability of this portion is bad. Further,because oil separation chamber 108 (cylinder part) is formed in acylindrical shape, there is a restriction in the space for installingthe oil separation part, and the entire length of the casing alsobecomes great. Therefore, the productivity is bad and the freedom oflayout is small.

Further, because parts such as separation pipe 109, snap ring 110 andseal bolt 111 are necessary and the number of parts is great, the timerequired for assembly is long. Further, defectives are liable to occurin the press fitting process of separation pipe 109 or the fasteningprocess of seal bolt 111. Therefore, there are problems that theproductivity is bad and that the cost for both the production and theassembly is high.

Furthermore, although the compressed gas after oil separation isdischarged from discharge port 112 communicated with the space betweenthe lower end of seal bolt 111 and the upper end of separation pipe 109to outside of the compressor, because the freedom of the layout of theseparation mechanism part is small, the position of discharge port 112is also restricted. Therefore, there is a problem that there is not agreat freedom in position of discharge port 112 and restriction occursin design of compressor itself or in connection structure to outside.

Accordingly, paying attention to the above-described problems, an objectof the present invention is to provide a compressor with a built-in oilseparator which can improve the productivity and reduce the cost andwhich can ensure the design freedom for the position of discharge port,by simplifying the structure of an oil separation part.

Means for solving the Problems

To achieve the above-described object, the present invention provides awith a built-in centrifugal oil separator characterized in that the oilseparator is formed between a first member and a second memberconstituting a compressor by a coupled structure of the first member andthe second member.

More concretely, for example, the oil separator includes at least aseparation chamber separating an oil component and a gas component ofoil-containing gas introduced from a discharge chamber from each otherby utilizing a centrifugal force, a communication hole provided betweenthe separation chamber and the discharge chamber, and a lower holeleading oil separated in the separation chamber down to an oil storagechamber positioned under the separation chamber, and these are formedbetween the first member and the second member by the coupled structureof the first member and the second member.

Namely, since the cylinder part (separation chamber) of the oilseparation mechanism, the communication hole part and the lower holepart are formed by the coupled structure of the first member and thesecond member constituting the compressor, it becomes possible to formthese parts without performing machine processing, and therefore, theproductivity can be greatly improved, and it becomes possible to reducethe cost. Further, because the separation pipe in the conventionalstructure can be abolished and the fixing or engaging mechanism thereof,and further the seal bolt, can be abolished, the structure of the wholeof the separation mechanism can be simplified, and because the number ofparts can be greatly decreased, shortening of the assembly time,facilitation of the assembly and reduction of the cost may be expected.Further, as the result of abolishment of the seal bolt, etc., it becomespossible to shorten the entire length of the oil separation part andmake the part smaller, thereby making the whole of the compressor small.

Further, in the present invention, a structure may be employed wherein agas passageway is provided between the above-described oil separator anda discharge port connected to outside of the compressor, and the gaspassageway is also formed between the first member and the second memberby the coupled structure of the first member and the second member. Thedischarge port may be communicated to this gas passageway, therebysmoothly discharging the gas separated from oil to out side from thedischarge port.

In this compressor with a built-in oil separator according to thepresent invention, although the oil separator is formed basically as acentrifugal oil separator, because the number of parts is small andthere is no part performed with machine processing, the freedom of shapeof the separation chamber is kept remarkably high. Therefore, theseparation chamber can be formed either in a cylindrical shape whosegenerating line extends straightly, or in a cylindrical shape whosegenerating line is curved (a separation chamber formed as adoughnut-like shape as a whole (a shape forming a part of a doughnutshape)). In particular, by forming this separation chamber in acylindrical shape (a doughnut shape) having a curvature, the freedom forlayout may be greatly increased, and it becomes possible to make thewhole of the compressor compact.

Further, with respect to the cross-sectional shape in theabove-described cylindrical shape, although a substantially perfectcircle is preferable, from the viewpoint of the coupled structure of thefirst member and the second member, it may be a structure wherein thereis a small step in the inner surface of the cylindrical shape or whereinthere is a difference in curvature between the arcs in the crosssections of the cylindrical shapes of the first member and the secondmember which form the inner surface of the entire cylindrical shape.Further, with forming the inner surface of the cylindrical shape, adifference in circumferential length may occur between the first memberand the second member. Furthermore, a difference in depth may occurbetween arc-like grooves in the respective cylindrical cross sections ofthe first member and the second member which form the inner surface ofthe entire cylindrical shape.

Further, in order to avoid reduction of separation ability caused by theabolishment of a separation pipe, it can be realized to exhibit the samelevel of separation ability as that in the conventional structure bychanging the discharge direction of the compressed gas being dischargedthrough the communication hole into the oil separation chamber ascompared with the discharge direction in the conventional structure. Forexample, by employing a structure wherein an opening of thecommunication hole toward the separation chamber is directed to the oilstorage chamber side, it becomes possible to efficiently separate oiltoward the oil storage chamber side while effectively operating thecentrifugal force for separation on the oil.

It is possible to provide a plurality of communication holes directed tothe separation chamber. In this case, a structure may be employedwherein openings of the plurality of communication holes toward theseparation chamber are directed in a same direction. In such astructure, even in a case where the amount of gas discharged to the oilseparation chamber is relatively great, the discharge conditions of therespective communication holes may be optimized, and it becomes possibleto introduce the efficiently separated oil into the oil storage chamber.Further, a structure may also be employed wherein directions of openingsof the plurality of communication holes toward the separation chamberare changed from each other. In such a structure, the direction of gasdischarged into the oil separation chamber is changed in angle for eachcommunication hole, it becomes possible to discharge the gas inaccordance with the shape of the oil separation chamber, an efficientseparation becomes possible, and it becomes possible to introduce theefficiently separated oil into the oil storage chamber.

Further, a structure may also be employed wherein a stepped portion or aweir portion is provided in the above-described gas passageway. By sucha device of the shape of the gas passageway provided between theseparation chamber and the discharge port, the flow of oil out of thedischarge port may be decreased.

Furthermore, a structure may also be employed wherein a second dischargechamber (a chamber provided immediately before the discharge port, whichis different from the aforementioned discharge chamber) is formedbetween the above-described separation chamber and the above-describeddischarge port. In such a structure, because the second dischargechamber may be merely communicated with the discharge port, the freedomin position to be set for discharge port may be greatly increased byadequately setting the region to be formed with the second dischargechamber and the shape thereof.

Although such a structure for the compressor with a built-in oilseparator according to the present invention can be applied tosubstantially any type compressor, and in particular, it is suitable fora scroll-type compressor. In case of a scroll-type compressor, astructure may be employed wherein one of the above-described firstmember and the above-described second member is a fixed scroll formingmember, and the other is a compressor casing.

Effect According to the Invention

Thus, in the compressor with a built-in oil separator according to thepresent invention, an oil separator can be formed by the coupledstructure of the first member (for example, a fixed scroll formingmember) and the second member (for example, a casing) without machiningcylinder, communication hole, separation pipe holding part, lower hole,etc. in the conventional structure, and the separation pipe in theconventional structure can be abolished, and therefore, the followingeffects may be obtained.

(1) Improvement in productivity on processing and reduction in cost maybe achieved by abolishment of machining for oil separation part.(2) Reduction in cost and improvement in assembly as a single structuralpart may be achieved by decrease of the number of parts.(3) The process for assembly may be greatly simplified, the processesfor press-fitting of a separation pipe and fastening of a seal bolt,which were necks in the conventional structure, can be omitted,defectives in those processes in the conventional structure do notoccur, and the rate of defectives in the assembling process may begreatly reduced.(4) The freedom in position of discharge port may be greatly increased,thereby greatly improving the layout performance of the discharge port,ultimately, the layout performance as the whole of the compressorincorporated into a system.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a portion including a dischargechamber in a compressor with a built-in oil separator according to anembodiment of the present invention.

FIG. 2 is a partial sectional view (a sectional view in a directionacross an oil separator) of an oil separator part of the compressordepicted in FIG. 1.

FIG. 3 is a partial sectional view of a lower hole part at the lower endof an oil separator of the compressor depicted in FIG. 1.

FIG. 4 is a partial sectional view (a sectional view in a verticaldirection of an oil separator), showing examples of sectional shapes foran oil separator part of the compressor depicted in FIG. 1.

FIG. 5 is a partial sectional view of a gas passageway part of thecompressor depicted in FIG. 1.

FIG. 6 is a partial vertical sectional view of a conventional compressorwith a built-in oil separator.

EXPLANATION OF SYMBOLS

1: compressor with a built-in oil separator2: discharge chamber3: oil separator4: fixed scroll forming member as first member5: casing as second member6: separation chamber7: communication hole8: oil storage chamber9: lower hole10: orifice11: gas passageway12: discharge port13: stepped portion (or weir portion)14: second discharge chamber15: region capable of being formed with discharge port

THE BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, desirable embodiments of the present invention will beexplained referring to figures.

FIG. 1 depicts a cross section of a part including a discharge chamber 2of a compressor with a built-in oil separator 1 according to anembodiment of the present invention. This compressor 1 is formed as, forexample, a scroll-type compressor having the aforementioned compressionmechanism 103 comprising fixed scroll 101 and movable scroll 102 asshown in FIG. 6. In the compression mechanism 103, compressed gas (forexample, refrigerant gas) is introduced into discharge chamber 2 throughdischarge hole (refer to FIG. 6).

Oil separator 3 is built in at an appropriate position around dischargechamber 2. As shown also in FIGS. 2 and 3, this oil separator 3 isformed by the coupled structure of a fixed scroll forming member 4provided as a first member and a casing 5 provided as a second member.Oil separator 3 has a cylinder-structured separation chamber 6 whichseparates oil from the compressed gas by centrifugal force, and in thisembodiment, separation chamber 6 is formed in a cylindrical shape whosegenerating line is curved (a cylindrical shape forming a part of adoughnut shape). A communication hole 7 is provided between separationchamber 6 and discharge chamber 2 for discharging gas containing oilfrom discharge chamber 2 into separation chamber 6, and in thisembodiment, a plurality of (two) communication holes 7 are provided. Asdepicted in FIG. 2, oil containing gas (shown by arrow) is introducedinto separation chamber 6 through communication hole 7 at a positioneccentric from the center axis of the cylindrical shape of separationchamber 6, the flow along the inner surface of separation chamber 6 isformed, and oil in the gas is separated by centrifugal force. Asdepicted in FIG. 4, the openings of two communication holes 7 aredirected toward the side of oil storage chamber 8 formed underseparation chamber 6, and in the embodiment depicted in FIG. 1, as shownin FIG. 4(B), the directions of the openings toward separation chamber 6are changed for the respective communication holes 7 from each other,namely, the angles of the hole extending directions of the respectivecommunication holes 7 are changed from each other. Communication hole 7located at a lower position is set in angle so as to be more directed tooil storage chamber 8 side. In such a case where a plurality ofcommunication holes 7 are provided, as shown in FIG. 4(A), a structuremay be employed wherein the openings toward separation chamber 6 of therespective communication holes 7 are set in a same direction and theopenings of all communication holes 7 are directed in an optimumdirection. The separated oil is stored in oil storage chamber 8 througha lower hole 9 provided at the lower end of separation chamber 6. Asdepicted in FIG. 3, lower hole 9 is formed at a position eccentric fromthe center of the cylindrical shape of separation chamber 6. The oilstored in oil storage chamber 8 is returned to the suction chamber sidethrough orifice 10.

The oil separate in separation chamber 6 is discharged to outside of thecompressor from discharge port 12 through gas passageway 11 communicatedwith the upper end of separation chamber 6. In this embodiment, asdepicted in FIG. 5, a stepped portion 13 (or a weir portion) is providedin gas passage way 11, and by the presence of stepped portion 13, theflow in gas passageway 11 is bent, and it is suppressed that the oilflows out to outside from discharge port 12.

Further, in this embodiment, between separation chamber 6 and dischargeport 12 (in this embodiment, at a position after the above-describedstepped portion 13), a second discharge chamber 14 different from theabove-described discharge chamber 2 is formed. Although discharge port12 is communicated with this second discharge chamber 14, because seconddischarge chamber 14 is formed as a chamber having a certain length inthe circumferential direction of the compressor as shown in FIG. 1, theposition of discharge port 12 capable of being located may be freely setas long as it is within the range corresponding to the extending regionof this second discharge chamber 14 (15: region capable of being formedwith discharge port).

In the compressor with a built-in oil separator 1 forming a scroll-typecompressor thus constructed, in particular, by forming separationchamber 6, lower hole 9 and communication hole 7 by the coupledstructure of fixed scroll forming member 4 and casing 5, they can beeasily formed merely by assembling fixed scroll forming member 4 andcasing 5. Namely, because the oil separator forming part comprisingfixed scroll forming member 4 and casing 5 can be formed by casting,machine processing for the cylinder part, etc. in the conventionalstructure is not necessary at all. Further, the separation pipe, theseal bolt, etc. in the conventional structure become unnecessary, andthe number of parts may also be greatly decreased. Consequently, theassembly may be facilitated, the time for assembly may be shortened,occurrence of defectives in assembly may be greatly decreased, and greatimprovement in productivity and reduction in cost become possible.

Further, with respect to a fear of reduction in oil separation abilitywhich may be ascribed to abolishment of a conventional separation pipe,by setting the discharge direction from one or a plurality ofcommunication holes 7 to oil separation chamber 6 at a direction towarda lower part, it becomes easy to introduce oil into oil storage chamber8 side (in the conventional separation structure, the discharge has beencarried out in a direction perpendicular to the axial direction of theseparation chamber), and further, by changing the angles of therespective communication holes 7 from each other, a more efficientseparation becomes possible.

Further, as the shape of separation chamber 6, although any of thecylindrical shape whose generating line extends straightly similarly inthe conventional structure and the doughnut-like cylindrical shapehaving a curvature as in this embodiment is possible, by employing thedoughnut-like cylindrical shape as in this embodiment, the freedom inlocation and shape of separation chamber 6 may be increased, the freedomin layout thereof may be greatly increased, and it may contribute tomake the whole of the compressor compact. As to the cross-sectionalshape of the cylindrical shape, as aforementioned, as needed, it is notalways a perfect circle, and further, there may be a difference infunction for forming the cross-sectional circular shape between thefirst and second members.

Further, by providing stepped portion 13 in gas passageway 11 afterpassing through oil separation chamber 6, it becomes possible to greatlyreduce the amount of oil flowing out to an external circuit side fromdischarge port 12. Furthermore, by providing second discharge chamber 14at a position after passing through separation chamber 6, the freedom insetting of position of discharge port 12 may be greatly increased.

INDUSTRIAL APPLICATIONS OF THE INVENTION

The structure of the compressor with a built-in oil separator accordingto the present invention can be applied to any type compressorincorporated with an oil separator, and in particular, it is suitablefor a scroll-type compressor.

1. A compressor with a built-in centrifugal oil separator characterizedin that said oil separator is formed between a first member and a secondmember constituting a compressor by a coupled structure of said firstmember and said second member.
 2. The compressor with a built-in oilseparator according to claim 1, wherein said oil separator includes atleast a separation chamber separating an oil component and a gascomponent of oil-containing gas introduced from a discharge chamber fromeach other by utilizing a centrifugal force, a communication holeprovided between said separation chamber and said discharge chamber, anda lower hole leading oil separated in said separation chamber down to anoil storage chamber positioned under said separation chamber.
 3. Thecompressor with a built-in oil separator according to claim 1, wherein agas passageway is provided between said oil separator and a dischargeport connected to outside of said compressor, and said gas passageway isalso formed between said first member and said second member by saidcoupled structure of said first member and said second member.
 4. Thecompressor with a built-in oil separator according to claim 2, whereinsaid separation chamber is formed in a cylindrical shape whosegenerating line extends straightly.
 5. The compressor with a built-inoil separator according to claim 2, wherein said separation chamber isformed in a cylindrical shape whose generating line is curved.
 6. Thecompressor with a built-in oil separator according to claim 2, whereinan opening of said communication hole toward said separation chamber isdirected to said oil storage chamber side.
 7. The compressor with abuilt-in oil separator according to claim 2, wherein a plurality ofcommunication holes are provided.
 8. The compressor with a built-in oilseparator according to claim 7, wherein openings of said plurality ofcommunication holes toward said separation chamber are directed in asame direction.
 9. The compressor with a built-in oil separatoraccording to claim 7, wherein directions of openings of said pluralityof communication holes toward said separation chamber are changed fromeach other.
 10. The compressor with a built-in oil separator accordingto claim 3, wherein a stepped portion or a weir portion is provided insaid gas passageway.
 11. The compressor with a built-in oil separatoraccording to claim 2, wherein a second discharge chamber different fromsaid discharge chamber is formed between said separation chamber and adischarge port connected to outside of said compressor.
 12. Thecompressor with a built-in oil separator according to claim 1, whereinsaid compressor is a scroll-type compressor, one of said first memberand said second member is a fixed scroll forming member, and the otheris a compressor casing.